I have a 1996 Hunter 430, in which Sea-water made its way to the oil recently. The engine is a Volvo MD22L, which is now in pieces on a pallet in the shop. The heat exchanger tests out with no leaks, and the head gasket was intact. It was not coolant in the oil, but water. Earlier this season, I had it hauled out for bottom paint and some repairs. One of the items "replaced" was a step-down connector (from 3" to 2 1/2" hose) that goes to the exhaust outlet. It was a custom built part out of fiberglass. My mechanic and I suspect that water may have come in from the exhaust outlet, and that possibly the original step-down connector may have had a safety valve in it to prevent the back-flow of water. Can someone send me a picture of the rear of their engine and the step down connector (in-place)? I don't know what the original part looked like. Also, if you have any good knowledgeable contacts at Hunter, please share, as I would like to know if that anti back-flow valve really existed in the original part.
Hunter 430 - Exaust return-water safety valve?
- Thread starter mikesher
- Start date
Don't know if you'd consider this.
Now that the engine is out, perhaps you might consider re-powering??
Have to be candid. I'm not a big volvo fan.
Now that the engine is out, perhaps you might consider re-powering??
I will definitely consider that option, depending on the repair estimate. As this may be still considered an "Event", I am hoping to get some insurance help with the cost. What engine would you suggest, Yanmar, or other?.
The only hose size changes I see on mine are on the xover from the sea water strainer to the water pump and a reducing fitting that goes into the back of the heat exchanger. The exhaust/hot water mixer appears to be cast steel. Both the reducing fitting mentioned above and the mixer are large enough to house something inside but I have no knowledge of that. The oil cooler is a suspect place to mix oil and water, and far less expensive to fix than a cracked block or head. good luck.
Getting sea water into an sea water cooled engine is pretty easy. Just crank it a good bit with out it starting and your set. fills up the exhaust and then it enters into the engine through the exhaust valve that is open (there is always one open).
Did this happen immediatly after you put on the reducer?
Did this happen immediatly after you put on the reducer?
Easier than I would have expected
That is exactly what happened. The engine has been hard starting since spring. What I know now, is that if the engine is hard to start, close the through-hull, start the engine, stop the engine, open the through-hull, then restart the engine... something I never knew until now..
The Volvo manual doesn't mention it.. But Yanmar manuals do (at least the new ones)
Hunter confirmed, that there is no return-water safety valve in the exhaust.
That is exactly what happened. The engine has been hard starting since spring. What I know now, is that if the engine is hard to start, close the through-hull, start the engine, stop the engine, open the through-hull, then restart the engine... something I never knew until now..
The Volvo manual doesn't mention it.. But Yanmar manuals do (at least the new ones)
Hunter confirmed, that there is no return-water safety valve in the exhaust.
Repowering
BTW, the cost to repair the engine after it was removed and torn-down exceeded the cost of a new Yanmar 4JH57, which is smaller, more powerful, and more fuel efficient. I'm officially going down the repower path now.. Currently waiting on the engine to arrive from Japan.
Fortunately my insurance is paying most of the bill, because it was tied to an 'event' earlier this spring when I sucked up some plastic and sea grass and overheated while cruising. After that, the Volvo was hard starting.
BTW, the cost to repair the engine after it was removed and torn-down exceeded the cost of a new Yanmar 4JH57, which is smaller, more powerful, and more fuel efficient. I'm officially going down the repower path now.. Currently waiting on the engine to arrive from Japan.
Fortunately my insurance is paying most of the bill, because it was tied to an 'event' earlier this spring when I sucked up some plastic and sea grass and overheated while cruising. After that, the Volvo was hard starting.